I have lost several loved ones to smoking related illnesses.
I absolutely hate seeing people puffing away, its awful.
I have never smoked because I don't want to increase the risk of dying a painful death, and I cant afford £7 a day or whatever it costs these days.
I don't ever mention this to people who I know smoke... Thankfully only one out of all my friends smokes - i wish she didn't but wont mention it as she would get the 'ump!
I do think YABU in the way you have worded the statement. It sounds so draconian, judgmental and rather faulty logic to bias an employment decision on a personal (legal) choice.